Seventy-eight patients successfully completed the study (45 women and 33 men aged from 31 to 76 years old) (Fig. 2). Two patients of test group did not show up both at the first and second controls. No patients were excluded or showed complications or adverse reaction. Results are shown in Table 1. The average number of implants per patients was 4.8 ± 3.4 in the control group and 4.4 ± 2.9 in the test one. Single crowns, implant-supported bridges, and Toronto bridge were included in both of the study groups. The values taken in consideration were recorded for both the dental implants and the rest of the dentition and compared at each time. All dental implant index values were higher when compared to the natural teeth ones while no differences were appreciable concerning the PPD. The study provided data for the test and control groups at three different time points. Analyzing the results, it can be observed for both groups a high decrease of BoP and PI values after 1 month after the baseline, related to the prophylaxis performed by dental hygienist.

The second part of the study described the re-colonization of dental implants and teeth surfaces: this was related to the proper use of oral hygiene devices, showing the effective difference of the manual and electric toothbrushes in preventing the new plaque formation and the consequent inflammation status.

The difference of PI recorded around implants at the beginning and the end of the study was statistically significant for both control and test groups (P < 0.0001). Observing in detail the second part of the study in Fig. 3, it was possible to observe how the test group kept reducing (P < 0.0001) while the control showed a mild increase (P = 0.68). Comparison at 3 months showed statistical significance (P < 0.05).

In Fig. 4 is shown the PI recorded around natural teeth: in this case, comparing the baseline with the data collected after 3 months was possible to observe high statistical significance only for the test (P < 0.0001) and significance for the control (P < 0.05; P = 0.031). Highlighting the second part, the different trend of test and control lines confirmed the higher performances of test devices (P < 0.0001) compared to the control that showed a mild increase (P = 0.16). Comparison between the two groups at 3 months was highly statistically significant (P < 0.0001).